The long range goals of the program are to contribute to a basic understanding of the pathophysiology of thrombus formation and resolution. Specific areas of investigation include: structure of adult and fetal fibrinogen; the mechanism of fibrin self-assembly; structure and function of the Cold-Insoluble Globulin of Plasma (CIg); pathways of fibrinogen turnover and catabolism; the nature of cellular fibrinogen synthesis, assembly, and secretion. Supplemental support is requested for expanded investigations of CIg: to determine the nature of its interactions with fibrinogen and other molecules; and to probe its role in certain clinical disease states. Supplemental support is also requested for revised and expanded investigations related to cellular fibrinogen synthesis, assembly, and secretion.